* Astronomy

Title: Resolved Dust Emission in a Quasar at z=3.65
Authors: D.L. Clements, Glen Petitpas, D. Farrah, E. Hatziminaoglou, T. Babbedge, M. Rowan-Robinson, I. Perez-Fournon, Antonio Hernan-Caballero, Nieves Castro-Rodriguez, C. Lonsdale, J. Surace, A. Franceschini, B.J. Wilkes, H. Smith

We present submillimetre observations of the z=3.653 quasar SDSS160705+533558 together with data in the optical and infrared. The object is unusually bright in the far-IR and submm with an IR luminosity of ~10^14 L_sun. We ascribe this luminosity to a combination of AGN and starburst emission, with the starburst forming stars at a rate of a few thousand solar masses per year. Submillimetre Array (SMA) imaging observations with a resolution ~1" show that the submm (850 micron) emission is extended on scales of 10--35kpc and is offset from the optical position by ~10 kpc. This morphology is dissimilar to that found in submm galaxies, which are generally un- or marginally resolved on arcsecond scales, or submm-luminous AGN where the AGN lies at the peak of the submm or molecular emission. The simplest explanation is that the object is in the early stages of a merger between a gas rich galaxy, which hosts the starburst, and a gas-poor AGN-host galaxy, which is responsible for the quasar emission. It is also possible that jet induced star formation might contribute to the unusual morphology.

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